16321631 has 2 divisors, whose sum is σ = 16321632. Its totient is φ = 16321630.

The previous prime is 16321619. The next prime is 16321633. The reversal of 16321631 is 13612361.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16321631 - 2¹⁸ = 16059487 is a prime.

It is a super-2 number, since 2×16321631² = 532791277000322, which contains 22 as substring.

Together with 16321633, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 16321597 and 16321606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16321633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8160815 + 8160816.

It is an arithmetic number, because the mean of its divisors is an integer number (8160816).

Almost surely, 2^16321631 is an apocalyptic number.

16321631 is a deficient number, since it is larger than the sum of its proper divisors (1).

16321631 is an equidigital number, since it uses as much as digits as its factorization.

16321631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 23.

The square root of 16321631 is about 4040.0038366318. The cubic root of 16321631 is about 253.6614778540.

Adding to 16321631 its reverse (13612361), we get a palindrome (29933992).

The spelling of 16321631 in words is "sixteen million, three hundred twenty-one thousand, six hundred thirty-one".